广州南沙湿地公园候鸟源肠杆菌科耐药性及产超广谱β-内酰胺酶基因监测调查

Surveillance of drug resistance and extended-spectrum beta-lactamase genes in Enterobacteriaceae from migratory birds in Nansha Wetland Park, Guangzhou

摘要:

【背景】耐药基因可通过水平转移在环境、动物和人体间发生转移，而远距离传播则主要通过候鸟的迁徙。耐药基因可通过水平转移和候鸟迁徙跨地区传播至禽畜和人类，引起公共卫生问题。【目的】分离广州南沙湿地公园候鸟粪便中肠杆菌科细菌，并鉴定菌种类别，研究其对常见抗生素的耐药性及携带的主要超广谱β-内酰胺酶(extended-spectrum beta-lactamase，ESBL)耐药基因，评估广州南沙湿地公园候鸟储存、携带耐药菌和耐药基因的风险。【方法】2019年1月-12月，采集广州南沙湿地公园候鸟粪便样本393份，并进行细菌分离、培养和鉴定。使用药敏检测板对细菌进行耐药性检测。PCR扩增待测细菌的bla_CTX-M、bla_TEM和bla_SHV耐药基因，测序并进行Blast比对。【结果】检出肠杆菌科细菌59株(检出率为15.01%)，主要优势菌为成团泛菌(36株，占肠杆菌科细菌61.02%)。肠杆菌科细菌的耐药率达89.83%，对头孢唑啉、磺胺异噁唑和氨苄西林耐药率分别为81.36%、52.54%和44.07%，多重耐药率达55.93%。另外检出7株耐碳青霉烯类肠杆菌科细菌。测序结果显示，所有粪便样本中检出23株细菌携带bla_TEM-1耐药基因(5.85%)。【结论】广州南沙湿地公园候鸟粪便中肠杆菌科细菌种类复杂，多重耐药率较高，而且有储存耐碳青霉烯类肠杆菌科细菌的风险，具有重要的公共卫生意义。

Abstract:

[Background] Resistance genes can be transferred among environment, animal, and human, and transferred for a long distance by migratory birds, thus posing a great threat to public health. [Objective] We isolated and identified the main Enterobacteriaceae bacteria from the feces of migratory birds in Nansha Wetland Park, Guangzhou, and explored the resistance to common antibiotics and the main resistance extended-spectrum beta-lactamase (ESBL) genes. On this basis, we assessed the risk of migratory birds in Guangzhou carrying and transferring resistance bacteria and genes. [Methods] From January to December 2019, 393 fecal samples were collected, and the bacteria were isolated, cultured, and identified. Through drug susceptibility test, the resistance of the bacteria was detected. PCR was performed to amplify the resistance genes bla_CTX-M, bla_TEM, and bla_SHV, followed by sequencing and BLAST alignment. [Results] A total of 59 Enterobacteriaceae strains (isolation rate 15.01%) were detected from the 393 fecal samples, among which Pantoea agglomerans (36 strains, 61.02%) was most abundant. Of the 59 strains, 89.83% were resistant to the tested antibiotics, and the resistance rates to cefazolin (81.36%), sulfisoxazole (52.54%), and ampicillin (44.07%) were particularly high. Moreover, 55.93% of the strains were resistant to multiple antibiotics. In addition, 7 strains were resistant to carbapenems. The sequencing result showed that 23 strains carried the resistance gene bla_TEM-1 (5.85%). [Conclusion] Enterobacteriaceae bacteria in the feces of migratory birds in Nansha Wetland Park, Guangzhou are intricacy, and the rates of drug resistance and multi-drug resistance are high. The result suggests the risk of the migratory birds carrying carbapenem-resistant Enterobacteriaceae bacteria, which has important public health significance.